The subject matter disclosed herein relates to probes with junction boxes, and more particularly, to the attachment of a probe to a junction box.
Some probes, such as but not limited to CO2 duct probe transmitters, can have a sensor assembly attached to a junction box. The sensor assembly can have a sensor housing enclosing or partially enclosing one or more sensors, and a sensor plate attached to one end of the sensor housing. The junction box can have an opening on one side to fit the sensor housing. The sensor housing can be inserted through the opening so that the sensor plate attached to one end of the sensor housing can mate against the inside surface of the side of the junction box with the opening, and the cylindrical sensor housing can protrude from the junction box. The inside surface of the junction box can have a mating area defined by walls that enclose an area to fit the shape of the sensor plate.
In some installations, a snap clip is aligned on each edge of the mating area on the inside surface of the junction box. Each snap clip has a base extending a short length along the end of the mating area and extending perpendicularly from the mating area of the junction box to a ramped portion overhanging the mating area and tapering toward the tip that is extended farthest from the mating area. In assembling the sensor assembly with the junction box, the sensor housing can be inserted through the opening through the mating area until the sensor plate contacts the ramped portion of the snap clips. The snap clips interfere with the further progression of the sensor plate, so an additional force is applied to press the sensor plate past the ramped portion until the sensor plate mates against the inside mating area of the junction box. The snap clips are intended to elastically deform or flex outward and then snap back to a non-flexed or non-deformed position after the sensor plate is pushed past the ramped, overhanging portion. When the ramped overhanging portion snaps back into the non-flexed or non-deformed position, the ramped overhanging portion is intended to retain the sensor plate against the mating area of the junction box. Each wall or snap clip base is intended to retain the sensor plate from sliding against the inside surface of the junction box in one direction.
The snap clip design can be prone to several deficiencies. During the first use, rather than elastically deforming when the sensor plate is pressed into place, the snap clip can be permanently deformed, compromising the strength, tightness, and proper fit with which the sensor plate is held to the junction box. The snap clip can also break. For example, the base wall can break or the tapered portion can sheer off or snap off. Permanent deformation and/or breaking become increasingly likely to occur with each repeated assembly or disassembly, which makes disassembly and reassembly after the initial assembly problematic. Disassembly is more complicated than assembly as the sensor plate cannot simply be pulled apart from the junction box. Snap clips must be pried back to allow the sensor plate to be pulled away freely, which increases the likelihood of breaking a snap clip either by improperly pulling away the sensor plate with one or more snap clips still obstructing, or by putting too much force on the snap clips when prying the snap clips back. When a snap clip breaks, the junction box must be replaced at additional cost.
Therefore, there is a need for a more durable and easier method and/or apparatus to assemble and disassemble a sensor assembly with a junction box.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.